Updated 2013 January 26
The equations for the light curves of comets that are currently visible use only the raw observations and should give a reasonable prediction for the current brightness. If the comet has not yet been observed or has gone from view a correction for aperture is included, so that telescopic observers should expect the comet to be fainter than given by the equation. The correction is about 0.033 per centimetre. Values for the r parameter given in square brackets [ ] are assumed. The form of the light curve is either the standard m = H0 + 5 log d + K0 log r or the linear brightening m = H0 + 5 log d + L0 abs(t - T + D0) where T is the date of perihelion, t the present and D0 an offset, if L0 is +ve the comet brightens towards perihelion and if D0 is +ve the comet is brightest prior to perihelion.
Observations of individual comets are given below in ICQ format.
Full details of recently discovered objects do not appear until they are available on the CBAT web pages, which is usually a fortnight after the publication of the IAUC.
In a communication to the Minor Planet Center on Mar. 3, R. Kracht suggested that, on the basis of the apparent motion, there was some loose association between C/1999 M3 and C/2000 O3 (cf. MPEC 2000-Q09), despite the evident difference in the usual orbital elements. Nevertheless, it can be noted that the perihelion directions are L = 103.9, B = +11.4 (degrees, J2000.0) for C/1999 M3 and L = 100.6, B = +10.8 for C/2000 O3. On Mar. 4, Kracht wrote that, again despite differences in the usual orbital elements, the perihelion direction for C/2000 O3 is close to the average value, L = 102.6, B = +9.7, for the four clear members of the Marsden group (cf. IAUC 4832). A more extended relationship among these comets is therefore suggested. [MPEC 2002-E18, 2002 March 7]
R. Kracht points out that, like C/1999 N6 (cf. MPEC 2002-F03), C/2001 Q7 (cf. MPEC 2001-R36) does not have a unique orbit solution, an alternative low-i solution being:
Comet T q e Peri. Node Incl. C CK01Q070 2001 Aug. 21.80 0.0445 1.0 54.77 43.95 13.28 XHe suggests that, with C/1999 M3 and perhaps C/2000 O3, these comets form part of the extended Marsden population (i.e., having the same longitude and latitude of perihelion). Indeed, we could say that these four comets belong to the Kracht group. [MPEC 2002-F43, 2002 March 22]
T. Makinen, Finnish Meteorological Institute, Helsinki, reports the discovery of another apparent comet (cf. IAUC 7327) from the second systematic survey of hydrogen Lyman-alpha emission appearing on SWAN images (wavelength range 10-180 nm) taken from the SOHO spacecraft during September-November 2000 (discovery observation below). Makinen notes that all comets brighter than total visual mag approximately 11 can be seen on the SWAN full-sky maps. The stated uncertainty in the reported positions is 0.5 degree due to the resolution of the SWAN instrument.
2000 UT R.A. (2000) Decl. m1
Sept. 19.658 11 35.9 -12 13 11.6
Further positional and orbital information, together with an
ephemeris to encourage searches of archival optical images, are
given on MPEC 2002-H41. Derived total visual magnitudes from the
Lyman-alpha fluxes (using a formula by Jorda et al. 1992, Asteroids,
Comets, Meteors 1991, 285): 2000 Sept. 21.77 UT, 10.8; Oct. 1.42,
10.0; 5.23, 9.4; 7.35, 8.4; 10.38, 7.7; 12.45, 7.3; 14.37, 7.5;
17.40, 7.8; 21.38, 7.9; Nov. 4.42, 8.2.
[IAUC 7885, 2002 April 25]
Brian Marsden notes [MPEC 2002-O35. 2002 July 22] that together with C/2001 Q7 (cf. the orbit on MPC 45182), C/2001 Q8, C/2001 R8 and C/2001 R9 above clearly form the nucleus of a group (involving also C/1999 M3 and C/2000 O3) whose existence was proposed by R. Kracht on MPEC 2002-E18; see also MPEC 2002-F03.
Magnitude estimates in ICQ format, Last observation 2002 April 18, updated 2002 April 20.
One of the brighter objects was 2002 J3, discovered by Kazimieras Cernis on May 13. I independently discovered it at 08:30 on May 14, however this was 18 hours after the discovery had been posted and by then the comet was very obvious. I should have spotted it the previous day as I had looked at the C3 images on Monday evening.
Brian Marsden notes on MPEC 2002-C28 that: While 2002 C3, like some 95 percent of the comets discovered by SOHO, is clearly a member of the Kreutz sungrazing group, it is rather less appreciated that as many as 11 of the two dozen or so non-Kreutz comets discovered by SOHO also seem to be interconnected. The close temporal pairs C/2000 C2-2000 C5, C/2000 C3-2000 C4 and C/2000 Y6-2000 Y7 were remarked on when these comets were announced (cf. MPEC 2000-C52, 2000-C53 and 2001-B08). There is also the pair C/1999 J6 (MPEC 2000-F30) and C/1999 U2 (MPEC 1999-U29), comets with i = 27 deg separated by more than five months. M. Meyer was the first to point out the similarity between the orbits of C/1997 L2 (MPEC 1997-M06, MPC 35205) and C/2001 X8 (MPEC 2002-B01, MPC 44505), comets with i = 72 deg separated by 4.5 years; it also appears that the poorly observed comet C/2001 E1 can be associated with this pair, if the orbit with i = 107 deg on MPEC 2001-F52 is replaced by the one with i = 73 deg on MPC 44505.
Two 19th mag objects of asteroidal appearance separated by < 1 degree and having similar, somewhat unusual motion were reported by LINEAR on Jan. 8.32. Further observations were made following placement of the objects on the NEO Confirmation Page, and prediscovery observations in Nov.-Dec. 2001 were identified at the Minor Planet Center in LINEAR and NEAT data. Orbit computations for the two objects gave very similar results (basically differing only in T) and showed that the objects were only 0.7 AU from Jupiter at discovery. Observations by T. B. Spahr and P. Berlind with the 1.2-m reflector at the F. L. Whipple Observatory on 2002 Jan. 11.4 UT showed that the objects had faint, narrow tails around p.a. 250 deg. Independent observations by R. H. McNaught with the 1.0-m reflector at Siding Spring on Jan. 11.6 showed that the first object, now designated C/2002 A1, was slightly diffuse with a very faint 25" tail in p.a. 260 deg, and that the second object, C/2002 A2, was almost stellar with a very narrow 20" tail in p.a. 250 deg. The respective discovery observations and orbital elements are given in MPEC 2002-A62 (which also contains all the relevant astrometry and ephemerides). The 2001 Dec. 13 and 17 observations of C/2002 A1 originally appeared on MPS 45271 under the designation 2001 XG_115. The minimum distances from Jupiter were < 0.4 AU around 2001 July 9 and 18 for C/2002 A1 and C/2002 A2, respectively. [IAUC 7788, 2002 January 11]
The latest orbits, on MPEC 2002-C58 and C69, gives them a periodic orbit of around 77 years.
An 18th mag object reported as asteroidal by LINEAR on January 13.23 has been noted by several CCD observers to be cometary: Jan. 19.9 UT, slightly diffuse, m_1 = 17.3 (J. Nomen, Barcelona, Spain); 20.6, 10" coma, m_1 = 17.3 (J. Broughton, Reedy Creek, Qld.); 21.2, fuzzy coma of diameter about 10" (R. Dyvig, Quinn, SD); 21.2, m_1 = 17.0, 22" tail in p.a. 250 deg (R. Fredrick, R. Trentman, and R. Gruenke, Louisburg, KS). [IAUC 7799, 2002 January 21]
Brian Marsden notes on MPEC 2003-A29 [2003 January 6] that the "original" and "future" barycentric values of 1/a are +0.000025 and +0.006179 (+/- 0.000005) AU**-1, respectively. The original value implies that the comet is a new visitor from the Oort cloud.
An apparently asteroidal object reported by LINEAR in early January (discovery position below) and considered of only moderate interest was also recognized at the Minor Planet Center to have been accidentally reobserved by LINEAR on three isolated nights in February and March, after which the orbit calculation suggested the object might be a comet. It was therefore listed on the NEO Confirmation Page. Observations with the 1.2-m reflector at Mt. Hopkins Observatory by P. Berlind and T. B. Spahr on Apr. 6.1 UT in poor conditions (high thin cirrus) showed that the images were softer than those of stars of similar brightness, and observations on Apr. 7.2 showed the slightly diffuse images of a definite comet.
2002 UT R.A. (2000) Decl. m2
Jan. 6.14531 2 32 53.60 +46 57 58.1 18.9
[IAUC 7869, 2002 April 7]
An 18th mag object reported as asteroidal in appearance by LINEAR on January 26.09, and posted on the NEO Confirmation Page, has been found to be cometary on CCD images taken by M. Tichy and J. Ticha at Klet (coma diameter 7"-8", on Jan. 29.8 and Feb. 1.8 UT; coma diameter 9" with m_1 = 17.7-18.0 and a faint tail in p.a. 165 deg on Feb. 4.8) and by A. Galad and L. Kornos at Modra ('slightly diffuse' on Feb. 1 and 2). [IAUC 7817, 2002 February 4]
An apparently asteroidal 19th mag object reported by LINEAR on January 23.40 and posted on the NEO Confirmation Page has been found to be cometary by M. Tichy and J. Ticha at Klet (coma diameter 6", with m1 = 17.2, and faint 9" tail in p.a. 90 deg on Feb. 3.05 UT) and by R. H. McNaught at Siding Spring (8" coma and 10" tail in p.a. 60 deg on Feb. 6.66). [IAUC 7821, 2002 February 6]
F. Shelly, Lincoln Laboratory, Massachusetts Institute of Technology, reports that an apparently asteroidal object of 19th mag, discovered by LINEAR on Jan. 26.12 (and placed on the NEO Confirmation Page) was found to show a clear tail in p.a. about 330 deg on Feb. 11.09 UT. T. B. Spahr, Harvard-Smithsonian Center for Astrophysics, reports that CCD images taken with the 1.2-m reflector at Mt. Hopkins on Feb. 12.13 show the object to be very faintly diffuse with a faint extension in p.a. 315 deg. [IAUC 7826, 2002 February 12]
An apparently asteroidal object of 20th mag discovered by William Kwong Yeung, Benson, AZ, on CCD images taken with a 0.45-m reflector near Apache Peak on Jan. 21.49 UT was identified by the Minor Planet Center with additional apparently asteroidal observations (including some in 1998 and 2000-2001) made at several observatories through its routine processing. Noting the unusual nature of its orbit, T. Spahr obtained unfiltered CCD observations with M. Calkins at the 1.2-m reflector on Mount Hopkins on May 5, 6, and 7 that show the object (m_1 about 17) larger than nearby stars of similar brightness and with a persistent faint tail about 5" long in p.a. 315 deg. [IAUC 7986, 2002 May 9]
It was numbered 172 in September 2005 following identification of images on Palomar Sky Survey plates from the previous apparition in October 1993. Pre-discovery images by Spacewatch in 1998, and LINEAR in 2000 were also identified.
Word has been received of the independent visual discovery of a comet by Kaoru Ikeya (Mori, Shuchi, Shizuoka, Japan; 0.25-m reflector, 39x; communicated by S. Nakano, Sumoto, Japan; coma diameter 2' with weak condensation; motion about 5' northeastward in 30 min) and by Daqing Zhang (near Kaifeng, Henan province, China; 0.2-m reflector; communicated by J. Zhu, Peking University; coma diameter 3').
2002 UT R.A. (2000) Decl. m1 Observer
Feb. 1.408 0 08.9 -17 42 9.0 Ikeya
1.47 0 09 -17 30 8.5 Zhang
[IAUC 7812, 2002 February 1]
Precise astrometry (Feb. 1-2) and the preliminary parabolic orbital elements given below appear on MPEC 2002-C03. Visual m_1 and coma-diameter estimates: Feb. 1.910 UT, 7.5:, 5' (P. M. Raymundo, Salvador, Brazil, 0.25-m reflector; independent discovery); 2.081, 9.5:, 3' (A. Hale, Cloudcroft, NM, 0.41-m reflector; thin clouds); 2.43, 8.8, about 4' (K. Yoshimoto, Yamaguchi, Japan, 20x100 binoculars); 2.47, 8.8, 3' (D. Zhang, Kaifeng, Henan, China, 0.20-m f/4.4 reflector, 28x, as used for the discovery on Feb. 1.47; comet more condensed than on previous day); 2.53, 9.1, 3' (A. Pearce, Nedlands, W. Australia, 0.2-m reflector); 2.53, 8.5, 5' (N. Brown, Quinns Rocks, W. Australia, 0.15-m refractor). [IAUC 7813, 2002 February 2]
B. G. Marsden (cf. MPEC 2002-D36) and S. Nakano have noted the similarity of the orbits of comets C/2002 C1 and C/1661 C1 and that numerical integration of the 2002 orbit backward yields a previous perihelion date within a couple of years of 1659, making the link rather likely. Additional selected visual m_1 estimates: Feb. 14.74 UT, 7.1 (H. Dahle, Copenhagen, Denmark, 9x63 binoculars); 18.95, 6.8 (J. G. de S. Aguiar, Campinas, Brazil, 11x80 binoculars); 20.10, 6.4 (A. Hale, Cloudcroft, NM, 11x80 binoculars); 21.77, 6.3 (A. Kammerer, Ettlingen, Germany, 9x63 binoculars); 24.76, 6.0 (M. V. Zanotta, Laino, Italy, 7x42 binoculars); 28.78, 5.3 (R. J. Bouma, Groningen, The Netherlands, 15x80 binoculars); Mar. 3.75, 4.8 (K. Hornoch, Lelekovice, Czech Republic, naked eye); 4.41, 5.2 (Y. Nagai, Yamanashi, Japan, 12x50 binoculars); 6.49, 5.2 (A. Pearce, Nedlands, W. Australia, 20x80 binoculars). [IAUC 7843, 2002 March 6]
M. Fujii, Fujii Bisei Observatory (FBO); K. Ayani, Bisei Astronomical Observatory (BAO); and H. Kawakita, Gunma Astronomical Observatory, report that low-resolution spectra of comet C/2002 C1 obtained with the FBO 0.28-m reflector on Mar. 3.41 UT show the Na I emission line at 589.3 nm. Confirming spectroscopy at higher resolution (0.05 nm) with the BAO 1.01-m reflector on Mar. 6.41 resolved the Na I D_1 and D_2 emission lines. The stronger D_2 line has an equivalent width of 0.5 nm and is blueshifted by -33 km/s, which is consistent with the geocentric velocity of the comet. [IAUC 7851, 2002 March 13]
C. W. Hergenrother, Lunar and Planetary Laboratory, reports that observations with the Catalina 1.5-m reflector on Mar. 3.11, 4.10, 5.10, 9.10, 10.10, and 26.10 UT by J. Barnes, J. Fortney, and himself, and with a 0.28-m reflector on Mar. 9.81 by G. Masi (Ceccano, Italy), show dust shells within 30" of the nucleus of comet C/2002 C1 on the sunward side. The shells display evidence of two discrete jets. [IAUC 7862, 2002 March 28]
H. E. Matthews, National Research Council, Victoria, British Columbia, and Joint Astronomy Centre, Hawaii (JAC); and T. B. Lowe, JAC, report pointed spectral-line observations of comet C/2002 C1 made at the James Clerk Maxwell Telescope, Mauna Kea, in the 1.3-mm and 0.8-mm bands: "The beamwidths to halfpower are about 21" and 13", respectively. We have detected the groundstate rotational transitions HCN 4-3 and 3-2, HNC 4-3 and 3-2 and CS 5-4. Observed integrated intensities (in mainbeam brightness K km/s) were: 3.65 and 0.71 (HCN 3-2, HNC 4-3, Mar. 23.95 UT), 4.10 (HCN 3-2, Mar. 28.82), 0.71 (HNC 3-2, Mar. 29.85), 18.4 (HCN 4-3, Mar. 30.98) and 4.47, 0.62 and 0.74 (HCN 3-2, HNC 3-2, CS 5-4, Apr. 7.93). CO has not been detected in two attempts (CO 3-2, Mar. 23.95 and CO 2-1, Apr. 7.93), the absolute upper limit to the peak signal being 0.1 K. The velocity width (km/s) to halfpower measured using the HCN lines was 2.6 (Mar. 23.93), 2.4 (Mar. 28.82), 2.2 (Mar. 30.98) and 2.2 (Apr. 7.87) and thus appears to show a decrease with increasing r." [IAUC 7876, 2002 April 13]
A. Lecacheux, Observatoire de Paris; and N. Biver, European Space Agency, ESTEC, on behalf of the Odin Solar System Topical Team and of the Odin Team, report: "The Odin submillimetric space telescope observed water lines in comet C/2002 C1 with a high spectral resolution (80 m/s) from Apr. 21.9 to 28.3 UT. The H_2O 110-101 line at 556.936 GHz was detected with a peak integrated line intensity of 21.6 K km s**-1 on Apr. 26.8 inside the 2' Odin beam. This corresponds to a preliminary water-production rate of 1.7 x 10**29 molecules/s, taking into account opacity effects. The 110-101 line at 547.676 GHz of the (^18)O isotopic variety of water was also detected. The average of Apr. 23.7-28.1 observations yields an integrated line intensity of 0.24 +/- 0.02 K km s**-1. Within model uncertainties, the inferred H_2^(18)O production rate is consistent with the terrestrial ^(16)O/^(18)O ratio." [IAUC 7910, 2002 May 28]
G. Cremonese, Istituto Nazionale di Astrofisica (INAF) and Osservatorio Astronomico, Padova; A. Boattini, M. T. Capria, M. C. De Sanctis, and G. D'Abramo, Istituto di Astrofisica Spaziale e Fisica Cosmica, CNR, Rome; and A. Buzzoni, INAF and Telescopio Nazionale Galileo (TNG), report observing the sodium distribution in the coma of comet C/2002 C1 on Apr. 20.17 UT, using the 3.5-m TNG reflector (+ high-resolution spectrograph SARG; resolving power 43000; spatial coverage 26") with a narrow-band filter to isolate the sodium-D lines. Two long-slit spectra (one parallel and the other perpendicular to the sun-comet vector) show cometary sodium emissions clearly visible due to the comet's geocentric velocity of -8.3 km/s. In the first spectrum, the sodium emissions are clearly asymmetric with respect to the slit center, corresponding to the nuclear region, extending to the edge of the slit in the tail direction (about 4000 km). Even in the second spectrum, a slight asymmetry is visible in the sodium emissions with stronger intensity toward the southwest, suggesting the presence of a sodium jet that is most likely related to a dust feature. [IAUC 7914, 2002 June 2]
J. E. Lyke, M. S. Kelley, D. C. Jackson, R. D. Gehrz, and C. E. Woodward, University of Minnesota (UM), report 1- to 12-micron photometry of this comet on May 22.37 UT at the Mt. Lemmon Observing Facility 1.52-m telescope (+ UM bolometer + IRTF narrowband 'silicate' filters). No evidence for strong silicate emission was observed at 11 microns; short-wavelength data were fit to a 5800-K reflected solar blackbody, while the observed spectral energy distribution at longer wavelengths yields a blackbody color temperature of 270 +/- 15 K. Observed magnitudes: [J] = 10.87 +/- 0.02, [H] = 10.42 +/- 0.01, [K] = 10.26 +/- 0.01, [L'] = 8.78 +/- 0.28, [M] = 6.49 +/- 0.29, [N] = 1.98 +/- 0.24, [8.81 microns] = 2.81 +/- 0.34, [10.27 microns] = 1.33 +/- 0.06, [11.70 microns] = 1.18 +/- 0.31, and [12.49 microns] = 0.34 +/- 0.31. [IAUC 7921, 2002 June 17]
Nakano, Muraoka and Sato note that there is a possibility that the comet is identical with comet 1532 R1. Brian Marsden notes on MPEC 2002-C111 : A parabolic orbit no longer adequately fits the observations, and a revolution period of 400-500 years is likely. There is a possibility that the comet is identical with C/1532 R1, as first suggested by S. Nakano on the basis of observations through Feb. 10.4.
Further observations render this possibility unlikely, but make it more probable that the comet is a return of comet 1661 C1. Brian Marsden notes on MPEC 2002-D36 [2002 February 26] : Numerical integration backward of the perturbed equivalent of the above unperturbed orbit solution yields a previous perihelion date in March 1659. This suggests a likely identity with C/1661 C1, which has T = 1661.1, rather than with C/1532 R1 (cf. MPEC 2002-C111). If this identity is confirmed it will be the longest period comet so far known to return.
[See also Kenji Muraoka 's orbit (in Japanese).
New elements are published on MPEC 2002-G38 [2002 April 10] and Brian Marsden notes that the orbital elements yield the year of the previous perihelion passage as T = 1660.2 +/- 0.1 (1 sigma).
New elements are published on MPEC 2002-H23 [2002 April 20] and Brian Marsden notes notes that the orbital elements yield the year of the previous perihelion passage as T = 1667.9 +/- 0.3 (gravitational 1 sigma).
The latest orbit by Nakano & Hasegawa, which includes non-gravitional parameters, uses prediscovery images from Palomar-NEAT taken on 2001 August 25. This gives a slightly longer period (by two years) than their ealier, linked orbit (see below).
Another recent orbit, which includes non-gravitional parameters, by Nakano & Hasegawa links C/1661 C1 with C/2002 C1 and and from this they have identified a comet seen in February 877 as being the same object. With this secure linkage they have further identified a comet seen in February 1273. With these linkages the perihelion dates are: 2002 March 18.98, 1661 January 29.06, 1273 February 4.79 and 877 February 13.66. They suggest that previous returns were in 458 July 31, 88 May and -269 December. They also provide the following notes:
Ichiro Hasegawa and I [Nakano] have found an identical comet in 877 with C/2002 C1. This comet was seen around Alpha Andromeda - Gamma Pegasus on Feb. 11 in the evening sky in Japan (Sandai Jitsuroku, Kanda, p.484). And also this comet was seen in the west sky during 15 days in March in Europe (Chronicon Navaliciense, Pingre, p.350). Ichiro gave me the following position in TT and we estimate T = 877 Feb. 13.5 TT for this comet.C877 877 02 11.45 00 35.0 +13 30 500Note, on the other hand the European comet in 877 was well observed in the morning sky. However the comet was also located in the low evening sky at this time. When we think that our twilight time is the astronomical twilight, the comet would be seen over western horizon during early March as a bright comet (m1 = 3).After we got a linkage orbit 877 - 2002, then we found another identical comet in 1273 who was recorded in Japan and Korea. Japanese comet was seen in the west of the evening sky on Feb. 5 (Moromori-ki, Kanda, p.547) and Korean comet was seen in the east of the morning sky on Feb. 17 ( Koryo-sa). Our linkage shows T = 1273 Feb. 4.8.
Hirohisa Sato provides the following information:
The comet of 11th February, 877 has a record in Japan. "On the 25th day in the first month of the first yaer of the Genkei reign-period a 'guest star' appeared to the west of the (Tung-) Pi (14th lunar mansion)."(Dainihonshi ch. 359; K; Hsi.) Ho Peng Yoke (1962)'s 'Ancient and Mediaeval Observations of Comets and Novae in Chinese Sources' p 176. Time is about 18:00?('Tori-no-koku').The comet of 5th February, 1273 has a record in Japan. "On the 16th day in the first month of the tenth yaer of the Bun-ei reign-period [5th February, 1273] a (hui) comet was seen....."(Dainihonshi ch. 359; K.). Ho (1962) p194. The observation on 11th April was a 'guest star' and is not this comet. (Sato)
The link with the comet of 1661 is good, but it seems to have been intrinsically brighter at that return. An explanation is that the comet's intrinsic brightness is variable, and this is clearly seen in the current light curve, which shows a slow brightening over the course of the apparition. Some orbit computers suggest that the comet of 1532 is also associated with this comet and may be the primary component of a fragmentation which occured over 1000 years ago, so it may be worth searching along the orbital track for further fragments.
King Charles II was crowned in 1660 and had created the Royal Society in the same year. In 1661, Isaac Newton was 18, and went up to Cambridge in June of that year. It is unlikely that he observed the comet as his notebook suggest that the first comet that he observed was the one of December 1664. Halley would have been too young to record the comet (he was 5), but later he computed an orbit similar to that of the 1532 comet and suggested a possible link. Charles Messier noted this possible link, but that it had been refuted by Mechain. The comet was observed and drawn by Hevelius. The optical quality of his telescope was far inferior to those of today and the features drawn may be imaginary. [The drawings are from Guillemin, 'The world of comets', 1877] The comet was thought to be a portent for 'Black Bartholomew's Day' when 900 non-conformist clergymen were ejected from their benefices following the Act of Uniformity of 1662. Succeeding bright comets were associated with the Plague and the Fire of London. The comet was illustrated by Johann Gabriel Doppelmayr in 1742.
Here is the excerpt from volume 1 of Cometography about C/1661 C1 from Gary Kronk:.
Discovered: 1661 February 3.2 (D=0.62 AU, r=0.48 AU, Elong.=23 deg.) Last seen: 1661 March 28.1 (D=0.99 AU, r=1.39 AU, Elong.=88 deg.) Closest to the Earth: 1661 January 29 (0.6062 AU) Calculated path: DEL (Disc), AQL (Feb. 6), SER (Mar. 26)The Polish astronomer Johannes Hevelius (1668) provided the most extensive set of observations of this comet. He discovered it on 1661 February 3.2, shortly after morning twilight had begun. Computations using the orbit below indicate the comet was then exiting the twilight after having passed only 17 degrees from the sun on January 28. Within a few days Hevelius estimated the tail length as 6 degrees and noted the comet appeared fainter than Alpha Aquilae. Hevelius noted a multiple structure of the nucleus on several occasions up to February 20. The comet was last detected on March 28.1 by Hevelius.
The observations of Eberhard Welper (Strasbourg, France) were included in the 1788 volume of the Berliner Astronomisches Jahrbuch. Welper first saw the comet on February 8 and said the tail extended 5 degrees and was perpendicular to the horizon. He noted the same orientation on the 9th. By the 10th Welper said the tail was basically extending perpendicular to the horizon, although he noted a slight tilt toward the west. Welper's observation of February 11 was his last, because of an extended period of bad weather.
In volume 46 of Travels and Explorations of the Jesuit Missionaries in New France (1899), Jerome Lalemant (superior of the Jesuit missions in New France, now Canada) wrote of this comet. He said, "the comet which was visible here, from the end of January to the beginning of March, was soon followed by the disasters of which those stars of evil omen are the forerunners." In describing its appearance, he said, "Its tail, extending westward, pointed toward us and seemed to threaten us with a flagellation, of which it was, to us, a brilliant but fatal portent." He continued, "it did indeed move from West to East, following the flight of the constellation of the Eagle, at whose head it appeared, although by another movement it tended a little Northward from us."
Marie de l'Incarnation (1671), superior of the convent at Quebec, Canada, wrote a letter to her son in 1661 September which also described this comet. She said, "A comet was seen, its rods pointed toward the earth. It appeared at about two or three o'clock in the morning and disappeared toward six or seven with the day. In the air was seen a man of fire, enveloped in fire. A canoe of fire was also seen and, towards Montreal, a great crown likewise of fire."
Edmond Halley (1705) and P. F. A. Mechain (1785) computed very similar parabolic orbits, with the former noting a similarity to the orbit of the comet of 1532. Mechain's orbit is given below. It indicates the comet reached a maximum declination of +6 degrees (apparent) on February 14. The orbits are as follows:
Computer T AOP AN (2000.0) i q e Halley 1661 Jan. 27.4868 (UT) 33.552 87.169 32.596 0.448510 1.0 Mechain 1661 Jan. 27.381 (UT) 33.450 86.562 33.015 0.442722 1.0Despite Halley's suggestion that C/1532 R1 and C/1661 C1 might be related, the idea was ignored until Nevil Maskelyne (1786) looked into the matter. Maskelyne took the elapsed time between the perihelion date of these two comets, added it to the 1661 perihelion date, and predicted the comet would arrive at perihelion around 1789 April 27. He added that assumed perturbations by Jupiter would probably cause the perihelion date to occur earlier, possibly as soon as late 1788. With an assumed perihelion date of 1789 January 1, he computed an ephemeris for the period of 1788 April 23 to 1789 January 1. Maskelyne said the comet could be recovered as early as 1788 September by observers near the equator or south of it, and added, "The Cape of Good Hope would be an excellent situation for this purpose." Early in 1788, both Johann Elert Bode and Capel Lofft made similar predictions for the probable return of this comet. However, despite the preparation and numerous searches, the comet was not found.Full moon: February 14, March 15 Sources: J. Hevelius (1668), p. 483; Marie de l'Incarnation (1671), pp. 263-4; E. Halley, Philosophical Transactions of the Royal Society of London, 24 (1705), pp. 1882-99; A. G. Pingr�, Cometographie (1784), p. 10; P. F. A. M�chain, Memoirs of the Pres. of Paris (1785), p. 395; Philosophical Transactions of the Royal Society of London, 76 (1786), pp. 426-31; N. Maskelyne, Gentleman's Magazine, 57 (1787), p. 59; Berliner Astronomisches Jahrbuch (1788), pp. 195-6; C. Lofft, Gentleman's Magazine, 58 (1788), pp. 1048-50; Berliner Astronomisches Jahrbuch (1790), pp. 184-6; The London and Edinburgh Philosophical Magazine and Journal of Science (Series 3), 7 (1835 Jul.), p. 37; Travels and Explorations of the Jesuit Missionaries in New France, Volume 46, edited by Reuben Gold Thwaites, Cleveland: The Burrows Brothers Company (1899), p. 205; S. K. Vsekhsvyatskij, Physical Characteristics of Comets (1964), p. 50; Journal of the Royal Astronomical of Canada, 70 (1976 Dec.), pp. 311-12.
Early observations suggested that it might be brightening quite rapidly. On February 5.77 I estimated it at 7.7 in the 20cm Thorrowgood refractor x40, however other observers made it a little fainter on the same evening. On February 9.77 I made it 8.1 in the same instrument x70, though this time other observers were indicating a brighter magnitude. The coma was well condensed, DC5 - 6, with a coma diameter of 4'. The comet was also easily visible in 14x100 and 20x80 binoculars. Observations on February 11 suggest a magnitude of about 7. Maciej Reszelski reports that the comet had reached 6.5 in 20x60B on February 15.72. On February 26.76 I observed the comet in rather bright twilight with 20x80B and estimated it at 5.9, with a 9' ion tail in pa 85. It was distinctly brighter on February 28.78 when I made it 5.6 with a 0.5 degree tail in pa 65. I observed it from Cambridge on March 21.83, estimating it at 3.6 in 7x50B with a 2.6 degree long tail. A naked eye observation on May 1.89 put it at around 4.5. An observation with 20x80B on May 22.91 put it at 6.1. An observation with 20x80B on May 31.94 put it at 6.4. Observations with 20x80 Vixen binoculars in Cornwall under very dark skies in mid July put the comet at around 9.5, but very diffuse.
Here are a few images:
Michael Jager March 6
David Strange March 7
Michael Karrer
March 11
an animation showing folding tail rays and a knot moving down the tail.
Jonathan Shanklin March 27 (my
first attempt, so not very good! Image taken with 20cm f14 refractor and
SX8 camera).
A suggestion from Michael Mattiazzo is that the earth passed through the orbital plane of the comet around June 24-25 and this may have contributed to the apparent slow fade in brightness.
889 observations received February 2 - June 30 give an aperture corrected preliminary light curve of m = 6.2 + 5 log d + 7.5 log r The comet is fading and has become very diffuse, making it hard to pick out in light polluted regions. Interestingly, the comet's absolute magnitude has slowly varied by around two magnitudes over the course of the apparition.
Observations in ICQ format, Last observation 2002 August 12, updated 2003 February 2.
R. Huber and F. Shelley, Lincoln Laboratory, Massachusetts Institute of Technology, report the discovery by LINEAR of an 18th mag comet on February 1.09 with a tail 42"-47" long in p.a. 12.5 deg. Cometary activity has been confirmed via CCD observations by A. Galad and L. Kornos at Modra on Feb. 1.8 (m_1 = 16.3, asymmetric coma extending 15" toward p.a. about 30 deg) and 2.7 UT (slightly diffuse with coma diameter about 10"), by J. Ticha and M. Tichy at Klet on Feb. 2.7 (coma diameter 10"), and by T. Payer at Duesseldorf, Germany, on Feb. 2.8 (coma visible, m_1 = 16.6). [IAUC 7815, 2002 February 2]
Brian Marsden notes on MPEC 2002-S08 that the "original" and "future" barycentric values of 1/a are +0.000393 and +0.000592 (+/- 0.000017) AU**-1, respectively. [2002 September 16] The "original value of 1/a suggests that this is not a new visitor from the Oort cloud.
An object reported as asteroidal by LINEAR (discovery observation below), given the designation 2002 CW_134 on MPS 50314, and later placed on the NEO Confirmation Page, has been found to show cometary activity: Mar. 19.0 UT, diffuse with coma diameter 13" (M. Tichy and M. Kocer, Klet, 1.06-m reflector); Mar. 23.0, diffuse, faint coma extended about 30" in p.a. 330 deg (G. Masi and F. Mallia, Campo Catino, Italy, 0.8-m reflector).
2002 UT R.A. (2000) Decl. m2
Feb. 7.47271 12 52 46.90 - 5 33 17.2 20.1
[IAUC 7858, 2002 March 23]
Observations made in mid August 2003 revealed the presence of a faint thin straight tail some 21" long, thus confirming the cometary nature of the object, although any coma was <6" in diameter. The further observations made since discovery confirm the perihelion date as June 22.1, perihelion distance at 2.05 AU and the period as 30.7 years.
N. Takato, T. Sekiguchi, and J. Watanabe, National Astronomical Observatory of Japan, obtained nine CCD images with the 8.2-m Subaru telescope of the apparently asteroidal object 2002 CE_10 (first reported by the LINEAR team, whose discovery observation is given below; originally announced on MPEC 2002-C83 and MPS 50101) on Aug. 22.4 UT that show a very faint, straight tail about 21" long in p.a. 212 deg; the tail is also present on shorter exposures from Aug. 21.5-21.6, when any coma as bright as the tail must have been < 6" in diameter. Recent astrometry, orbital elements (T = 2003 June 22, Peri. = 126 deg, Node = 147 deg, i = 145 deg, e = 0.79, P = 30.8 yr), and an ephemeris appear on MPEC 2003-R20. [IAUC 8193, 2003 September 3]
Observations in ICQ format, Last observation 2003 September 20, updated 2003 November 14.
Independent visual discovery reports of a comet have been received from Douglas Snyder and Shigeki Murakami. Available observations:
2002 UT R.A. (2000) Decl. m1 Observer
Mar. 11.514 18 55.2 - 0 46 13.0 Snyder
11.806 18 55.5 - 0 35 11 Murakami
D. Snyder (Palominas, AZ). 0.50-m f/5 reflector. Coma diameter
about 4', diffuse with little central condensation. Motion about
5' toward northwest during Mar. 11.469-11.514 UT. Observed again
Mar. 12.46-12.50.
S. Murakami (Matsunoyama, Niigata, Japan). 0.46-m f/4.5 reflector
(68x). Coma diameter 3'. Slight motion toward northeast in 30
min.
[IAUC 7850, 2002 March 12]
Brian Marsden notes on MPEC 2002-L42 [2002 June 10] that the "original" and "future" barycentric values of 1/a are +0.000289 and -0.000180 (+/- 0.000023) AU**-1, respectively. The original value implies that the comet is not a new visitor from the Oort cloud.
Doug Snyder has provided the following information to the comet mail list: I was using a magnification of 149x, which was providing me with a field of 32' on my 20" f/5 Obsession. Occasionally, I would boost the magnification up to 212x to look at a particular object, but not for sweeping the skies. This was a deliberate search, although I am relatively new at comet searching. I had spent only about 70 hours up to the time of the finding. A real lucky find! I have been deep sky observing for about 20 years.
Not that I'm too much of a believer in the psychic side of things, but my wife and I had gone out to dinner with another couple very involved in amateur astronomy and we ate at a Chinese restaurant (this was on Sunday evening, the evening before the discovery). After the meal, we received our fortune cookies. Mine read "You will soon be the center of attention". On every other occasion where I get one of these fortunes, I just toss it away. Well, on this particular evening, I stuck it in my shirt pocket and took it home with me. Well, I stayted up the entire night and it was 8 hours later that I came across the comet. Now, for the time being, I guess I've been at the center of attention! My wife wants to frame it - but gee, its only 70 x 13 mm!
Stargazer finds comet BY LYN SOUTHERLAND Sierra Vista Herald March 14, 2002
PALOMINAS - With his eyes on the skies and the strains of "Some Enchanted Evening" playing in the background, Doug Snyder made the discovery of a lifetime early Monday morning.
The amateur stargazer discovered a new comet streaking through the Aquila Constellation in the heart of the Summer Milky Way galaxy.
At 3:40 on Monday morning, he happened across "a little gray smudge" nestled in the Aquila Constellation. He did some quick research using a sky atlas and numerous databases, but couldn't locate any references to his find.
Trying not to get his hopes too high, Snyder checked the comet's location again. "The comet had moved a bit, but not too much, and I found it again fairly easily. Dawn was coming, and my view of the comet was fading, but by now I was becoming more sure of my discovery," Snyder said.
He immediately e-mailed news of his discovery to the Central Bureau for Astronomical Telegrams, the Harvard-affiliated clearinghouse for new discoveries. It was 4 a.m. and the world was being told the latest space find had been made at a small observatory in Southeastern Arizona.
Several anxious hours later, he received a reply. CBAT has spent the interim time researching his find, verifying Snyder's experience and credentials, and locating the comet. CBAT asked for additional information, which Snyder provided, and then he waited.
"It's been a whirlwind couple of days," Snyder said. "But yesterday (Tuesday), they finally let me know that I had really discovered a new comet."
26 observations received give a preliminary light curve of m = 8.0 + 5 log d + [10] log r
Observations in ICQ format, Last observation 2002 July 9, updated 2003 February 2.
An apparently asteroidal object discovered by LINEAR was given the designation 2002 EJ_57 (observations on MPS 55777-55778). Additional observations of the object were located during routine processing at the Minor Planet Center, and these indicated that the orbit was unusual. The object was then placed on the NEO Confirmation Page, resulting in CCD observations by J. Ticha and M. Tichy at Klet (diffuse with coma diameter about 10" on May 1.8 UT) and by R. H. McNaught at Siding Spring (circular coma with diameter about 7" on May 2.5) showing cometary activity.
2002 UT R.A. (2000) Decl. m2
Mar. 13.20032 10 24 33.18 + 8 23 58.4 18.5
[IAUC 7890, 2002 May 2]
S. Nakano, Sumoto, Japan, reports the visual discovery by Syogo Utsunomiya of a comet in morning twilight.
2002 UT R.A. (2000) Decl. m1 Observer
Mar. 18.844 21 44.6 + 5 26 10.0 Utsunomiya
19.844 21 48.3 + 6 14 10.0 "
S. Utsunomiya (Minami Oguni-machi, Aso-gun, Kumamoto-ken, Japan).
25x150 binoculars; comet diffuse with weak condensation; coma
diameter 1' on Mar. 18 and 1'.5 on Mar. 19.
[IAUC 7854, 2002 March 20]
The comet was highly condensed and showed a short tail when I observed it on April 6.14 and 7.15. The observations up to April 9 suggested that it was only brightening slowly and would reach mag 7 when brightest. Nicolas Biver, observing on April 10.16 noted a significant brightening, with the comet at magnitude 5.9, with a nearly stellar appearance, suggesting a recent outburst. The following morning he reported that the comet had brightened further, but had become more diffuse and showed jets. I was able to observe it in brightening skies on April 13.16 and estimated it at 5.6 in 20x80B. A further observation in poor conditions with slight mist on April 16.15 put the comet at 3.9. I glimpsed the comet in very hazy conditions on April 23.86, estimating it at 4.5, with a 0.4 degree long tail. On May 1.87 I estimated it at 6.3 in my new Vixen 20x80B, surprisingly easy, and with the Pleiades a beautiful sight just below the comet. Antonio Giambersio made it 5.2: on May 1.79 in 16x70B. Alexandre Amorim observed the comet with 20x80B on May 11.90 and estimated it at 8.3 and still very strongly condensed. Jose Aguiar observed it on May 17.89 and estimated it at 8.0 in 20x80B, with a very strongly condensed coma.
58 observations received to May 17 give a preliminary light curve of m = 10.4 + 5 log d + 17.2 log r
Observations in ICQ format, Last observation 2002 June 2, updated 2003 February 2.
Brian Marsden notes on MPEC 2002-L43 [2002 June 10] that the "original" and "future" barycentric values of 1/a are +0.004146 and +0.003921 (+/- 0.000098) AU**-1, respectively. The original value implies that the comet is not a new visitor from the Oort cloud.
Observations in ICQ format, Last observation 2002 June 1, updated 2003 February 2.
S. Pravdo, E. Helin, and K. Lawrence, Jet Propulsion Laboratory, report the discovery by NEAT, on CCD images taken on May 13.45 UT with the Palomar 1.2-m Schmidt telescope, of a 18th mag comet with nebulosity extending about 5" toward the southwest. Following posting on the NEO Confirmation Page, additional observations obtained elsewhere on May 13.9 confirm the cometary nature: P. Kusnirak at Ondrejov (0.65-m reflector; m_1 = 18.3, faint 7" coma slightly elongated to the southwest); M. Tichy and M. Kocer at Klet (1.06-m KLENOT telescope; compact coma of diameter 16"); and L. Kornos at Modra (0.6-m reflector; m_1 = 16.6, coma diameter about 15"). Additional observations made by LONEOS and LINEAR on May 4, 7, and 8 were then identified by the Minor Planet Center staff. [IAUC 7899, 2002 May 13]
Brian Marsden notes on MPEC 2003-G46 [2003 April 9] that the "original" and "future" barycentric values of 1/a are +0.000026 and -0.000278 (+/- 0.000007) AU**-1, respectively. The original value implies that the comet is a new visitor from the Oort cloud.
The comet will not reach perihelion until October 2003, at 3.6 AU. It could reach 13th magnitude when brightest. It was around 16th magnitude according to CCD observations in early April.
Observations in ICQ format, Last observation 2003 June 3, updated 2003 October 25.
The comet is distant and will reach perihelion at 5.7 AU in September 2003.
Brian Marsden notes on MPEC 2002-L45 [2002 June 10] that the "original" and "future" barycentric values of 1/a are +0.000010 and -0.000036 (+/- 0.000028) AU**-1, respectively, suggesting that this is a "new" comet.
Perihelion is at the end of July at 1.8 AU and the object is in a 6.6 year periodic orbit. It will brighten a little, but is unlikely to exceed 17th mag. It is a Jupiter family comet.
The comet is distant and just past perihelion at 3.2 AU.
The comet is faint and distant. It reached perihelion at 5.2 AU in early January 2002.
Brian Marsden notes on MPEC 2003-K06 [2003 May 17] that the "original" and "future" barycentric values of 1/a are +0.001782 and +0.001827 (+/- 0.000009) AU**-1, respectively, suggesting that this is not a "new" comet.
It will reach perihelion in July, at 2.8 AU. It is periodic, with a period of around 63 years. It will brighten a little.
It will reach perihelion in 2004 April at 7.0 AU and will brighten a little when nearer perihelion. By July 2003 it had reached 16th magnitude.
Brian Marsden notes on MPEC 2003-P13 [2003 August 5] that the "original" and "future" barycentric values of 1/a are +0.000034 and +0.000074 (+/- 0.000004) AU**-1, respectively, suggesting that this is a "new" comet from the Oort cloud.
An apparently asteroidal object with not-unusual motion recorded by the LINEAR project on 2002 June 5.30, and linked over 2002 June 5-13 and designated by the Minor Planet Center as 2002 LZ_11 (but indicated on MPEC 2002-L64 as having a cometary orbit), was accidentally reobserved by LINEAR on numerous occasions in July 2002 and during July-Nov. 2003 (and by LONEOS on 2003 Oct. 16). E. Christensen, University of Arizona, recognized 2002 LZ_11 as having cometary appearance yesterday in CCD images (mag 16.6-16.9) obtained accidentally by the Catalina Sky Survey (0.68-m f/1.8 Schmidt) on 2003 Oct. 29. Further images yesterday by Christensen apparently confirmed the cometary appearance, as did images obtained today at the request of the Minor Planet Center by J. Young (0.61-m reflector at Table Mountain Observatory), who described the object as having a round coma, 7" across, with a featureless fanshaped tail about 15"-20" long in p.a. 190-280 degrees. [IAUC 8240, 2003 November 18]
On July 22, a report of an apparent visual comet discovery of a 12th mag comet on July 22.00 was received from Sebastian Hoenig, Dossenhiem, Germany. The object clearly showed motion to the north. Due to poor initial positions and bright moon, attempts to recover the object visually by A. Hale (Cloudcroft, NM) and Hoenig were unsuccessful. On July 27, S. Nakano (Sumoto, Japan) reported that K. Kadota (Ageo, Saitama, Japan), following a request by A. Nakamura (Kuma, Ehime, Japan), successfully imaged a comet while searching for the object reported on July 22. Additional observations were received after the comet was posted on the NEO Confirmation Page. [IAUC 7939, 2002 July 27]
Sitko, Lynch, Russell, Hammel and Polomski report similar spectroscopy of comet C/2002 O4 on Aug. 1.54 UT: "The infrared flux peaked near 10 microns, suggesting a temperature of around 280 +/- 20 K (equilibrium blackbody temperature = 243 K). There was a silicate-emission feature between about 8.5 and 11.5 microns extending about 20 percent above the continuum. Narrow-band [M] and [N] magnitudes were 9.7 and 4.4, respectively, both +/- 0.1." [IAUC 7950, 2002 August 8]
Several observers have noted that this comet has lost its condensation and is fading rapidly. K. Kadota, Ageo, Saitama, Japan (0.30-m reflector) reports (via S. Nakano) m_1 = 13.3 on a CCD image taken on Oct. 10.82 UT, but Y. Ezaki (Toyonaka, Osaka, Japan, 0.20-m reflector) could not find the comet to mag about 15 on an image taken two nights later. [IAUC 7995, 2002 October 17]
The latest orbit on MPEC 2002-S10 has a note from Brian Marsden that 'the "original" and "future" barycentric values of 1/a are -0.000717 and -0.000253 (+/- 0.000031) AU**-1, respectively.'[2002 September 16] It is somewhat unusual for a comet to have a negative "original" value for 1/a and this is one of the largest on record. It is possible that 'non gravitational' effects should be applied to the comet's orbit.
After my return from the ACM meeting in Berlin (where I met up with Sebastian and Maik Meyer) I was able to observe the comet on August 4.9. I estimated it at 9.5 in the Thorrowgood refractor x40, with a 3' coma and DC3. The comet may be brightening quite rapidly as several reports on August 6 put the comet as bright as 8th magnitude. I observed it with 20x80 binoculars on August 10.91 and made it 7.8.
A photograph taken on August 8.83 by Toni Scarmato shows a green coma, characteristic of Swan band emissions.
A suggestion from Michael Mattiazzo is that the earth passed through the orbital plane of the comet around August 13-14 and this may have given the apparent rapid rise in brightness.
Observations suggest that after an initial rapid brightening, the comet peaked in brightness around a month before perihelion. It then began to fade slowly until the equinox, when a more rapid decline set in. The latest image from Giovanni Sostero, taken on September 30, shows a diffuse coma with only a faint condensation, typical of a disintegrating comet. It seems unlikely that it will survive perihelion, unless it experiences an outburst comparable to 2000 WM1.
123 observations received to September 4 give a preliminary light curve of m = 8.1 + 5 log d + 6.6 log r
Observations in ICQ format, Last observation 2002 October 5 updated 2003 February 2.
The preliminary orbit suggests that it is in a short period orbit with P around 5 years and is near perihelion. It is intrinsically very faint (H0=19) and will fade. The orbital period is the third shortest of current P/ comets. At a favourable return it can pass 0.2 AU from the Earth.
Akimasa Nakamura provides the following discovery report:
Masayuki Suzuki posted the discovery circumstances of C/2002 O6 to the comet-obs mailing list (in Japanese). According to that, although he is a frequent visitor to the SWAN webpage (and has checked images time to time since this spring), his discovery of O6 was accidental.M. Suzuki, Utsunomiya, Tochigi, Japan, reports the discovery of a comet on publicly accessible images taken with the SWAN instrument on the SOHO spacecraft on July 25 and 27 UT. Prediscovery images were found on images taken as early as July 13. Visual confirmation has been reported by A. Hale, Cloudcroft, New Mexico, with a 0.20-m reflector (coma diameter 4'; magnitude measurement hampered by twilight, moon and clouds). CCD frames taken by J. Broughton, Reedy Creek, Australia, with a 0.25-m reflector also confirm the object's cometary nature.Inspired by Sebastian's discovery, he downloaded SWAN images taken on 25th and 27th of July, to see whether he could find C/2002 O4 or not. He found TWO moving objects: dimmer one was C/2002 O4, and the brighter one looked like C/2001 Q4 (NEAT). But, he noted the latter should have been much fainter because Q4 was around 16 mag.... it might be a new comet! He considered a possibility to observe it by himself on the night of his discovery (July 31th), but gave up due to bad weather and its position (way out of his observable sky). So, he sent his discovery report to the CBAT without confirmation. (He is an astrometrist at code 347, BTW.)
He also noted the comet was visible on the images taken on 13, 16, 18, 20th as well (faint, though), and later measured their positions and sent them to the CBAT in response to the request by Carl Hergenrother.
2002 UT R.A. (2000) Decl. m1 Observer
July 13 1 56 -34 12 Suzuki
16 2 08 -33 11 "
18 2 11 -31 11 "
20 2 25 -29 10 "
25 2 53 -25 9 "
27 3 10 -22 9 "
Aug. 1.451 3 53.73 -13 58.7 9.5 Hale
[IAUC 7944, 2002 August 1]Schmidt photographs of C/2002 O6 taken by M. Jaeger near Vienna on Sept. 13.125 UT show no nuclear condensation and a 4' x 1' coma of total mag about 9.5 with an 8' tail in p.a. 0 deg. K. Kadota, Ageo, Japan, reports (via S. Nakano, Sumoto, Japan) that his images taken on Sept. 10.809 and 17.813 also show no condensation, the coma having faded from m_1 = 11.2 to 12.1 during the past week. Visual m_1 estimates: Aug. 22.07, 6.2 (B. H. Granslo, Fjellhamar, Norway, 12x50 binoculars); 29.07, 7.6 (Granslo); Sept. 1.84, 8.1 (R. J. Bouma, Groningen, The Netherlands, 15x80 binoculars); 13.14, 10.0: (Bouma; twilight; altitude 11 deg; difficult object). [IAUC 7974, 2002 September 20]
Observations in early August showed that it was slowly brightening and it reached around mag 6. I observed it after a long meteor watch on August 12/13 and found it an easy object in 20x80B. Reports by Bjorn Granslo at the end of August show that it has faded significantly to around 7.5. Observations by myself in early September suggest that the fade is continuing, with the comet at mag 8
56 observations received to September 3 give a preliminary light curve of m = 9.2 + 5 log d + 4.1 log r
Observations in ICQ format, Last observation 2002 September 11, updated 2003 January 2.
M. Mattiazzo, Wallaroo, South Australia, reports that a CCD image taken by himself on Sept. 27.8 UT showed that this comet had apparently disrupted, revealing only a diffuse sunward-pointing 'antitail' of debris. Requests from the Central Bureau were sent to several observers at the time, seeking confirmation and additional details. Nothing further was received. But now, G. P. Tozzi (Istituto Nazionale di Astrofisica, Arcetri), along with H. Boehnhardt, O. R. Hainaut, F. Selman, I. Saviane, M. Pizarro, G. Roman, and F. Labrana, report that they searched for the comet on Dec. 3 (when its predicted total magnitude was about 10) with several telescopes at the European Southern Observatory, including the 2.2-m reflector (R filter), the New Technology Telescope (+ JHK filters), and the 3.6-m reflector (+ VRi filters); the comet could not be detected to a limiting magnitude of R about 20.5 within an area 30' x 30' centered at its predicted position. [IAUC 8250, 2003 December 4]
Brian Marsden notes on MPEC 2003-A30 [2003 January 6] that the "original" and "future" barycentric values of 1/a are +0.000027 and -0.000307 (+/- 0.000024) AU**-1, respectively, suggesting that this was a "new" comet from the Oort cloud.
The comet brightened relatively slowly and no visual observations were made after July 2003 although perihelion was in September. CCD observations in late September by Michael Mattiazzo suggest that the nucleus has disintegrated.
26 observations received to September 3 give a preliminary magnitude equation of m = 9.9 + 5 log d + 4.0 log r prior to perihelion.
Observations in ICQ format, Last observation 2003 July 27, updated 2004 September 19.
It is in a periodic orbit of 8.1 years and perihelion at 3.2 AU and is a Jupiter family comet. It will fade.
The preliminary orbit suggests that it is a distant object past perihelion and will fade.
Brian Marsden notes on MPEC 2003-N25 [2003 July 7] that the "original" and "future" barycentric values of 1/a are +0.002012 and +0.002289 (+/- 0.000008) AU**-1, respectively, suggesting that this is not a "new" comet from the Oort cloud.
S. Adams, Lincoln Laboratory, Massachusetts Institute of Technology, reports the discovery of two comets, both with coma diameter about 90" and both in the same field and moving in the same direction on LINEAR images taken on Aug. 26.14 UT. Following posting on the NEO Confirmation Page, additional CCD observers have confirmed both objects to be cometary in appearance. On Aug. 26.9, P. Kusnirak (0.65-m f/3.6 reflector, Ondrejov) found C/2002 Q2 to be well condensed with a coma of diameter about 20" and V = 17.7, whereas C/2002 Q3 appeared very diffuse without condensation and coma diameter about 25". A. Galad (0.6-m reflector, Modra) reported C/2002 Q2 to be diffuse with m_1 = 17.2, and S. P. Laurie (0.35-m reflector, Church Stretton, U.K.) reported the same object as diffuse with an 8" coma. P. R. Holvorcem and M. Schwartz (0.36-m reflector, Cottage Grove, OR) found C/2002 Q2 to be diffuse with a coma of diameter about 17" and m_1 = 17.1 on Aug. 27.3, whereas they noted C/2002 Q3 to be 2-2.5 mag fainter with a hint of diffuseness. The available astrometry, together with the preliminary parabolic orbital elements given below (by B. G. Marsden) that confirm the apparent relationship of the two comets (with C/2002 Q2 as the primary component), appear on MPEC 2002-Q37. [IAUC 7960, 2002 August 27]
S. S. Sheppard and D. C. Jewitt, University of Hawaii, report that CCD images of C/2002 Q3 on Sept. 4.3 and 5.3 UT taken with the 2.2-m reflector at Mauna Kea show three separate fragments a few arcsec apart; the brightest, component A (R = 21.7; photometry through a 1"-radius aperture), appears elongated; component B was at R = 22.1 and component C at 22.6. The astrometric positions are given on MPEC 2002-R20.
Z. Sekanina, Jet Propulsion Laboratory, communicates: "Applying my model for the split comets and using a code developed recently by P. W. Chodas and myself, I determined from 46 differential astrometric observations of the C/2002 Q2-C/2002 Q3 pair, taken between Aug. 26 and Sept. 1 (MPECs 2002-Q37, 2002-Q50, 2002-Q51, 2002-R19, and 2002-R20), that C/2002 Q2 is the main comet, with companion C/2002 Q3 having broken off from it in 1969.2 +/- 5.1 yr at a distance of some 57 +/- 6 AU from the sun and > 30 AU south of the ecliptic. The separation velocity was only 0.15 +/- 0.04 m/s, and the secondary comet has been subjected to a relative deceleration of 33.2 +/- 5.1 units of 10**-5 solar gravitational acceleration. The mean residual from the solution is +/- 1".03. The time of separation may be even more uncertain than indicated, if the orbits depart significantly from parabolas. Because of too-limited information on the C/2002 Q3 system (see above) available at this time, the fragmentation sequence for its three components remains unclear, with two extreme scenarios possible: either they all separated from C/2002 Q2 a long time ago (say, before about 1985) or two of them were released very recently (during the past several months) from the third. If so, component C is the parent to component B and perhaps to component A as well, although A could have alternatively separated from B after B broke off from C. Continuing observations of these components should soon constrain the range of possible scenarios. If the relative configuration of A, B, and C remains essentially unchanged over a period of a few weeks, they all are old fragments. If their separations begin to increase rapidly (by a factor of about 2 or more in a couple of weeks) and the line joining them rotates toward the north-south direction, they are products of recent events. The predicted separation distances and position angles (for 0h TT) of C/2002 C3 from C/2002 C2 are: Sept. 3, 3137", 304.5 deg; 8, 3630", 314.0 deg; 13, 4110", 321.3 deg; 18, 4423", 326.5 deg; 23, 4452", 330.0 deg; 28, 4207", 332.2 deg; Oct. 3, 3800", 333.7 deg." [IAUC 7966, 2002 September 6]
Further to IAUC 7966, Z. Sekanina writes that he has calculated an improved set of fragmentation parameters based on 73 differential astrometric observations taken between Aug. 26 and Sept. 13 (MPC 46490-46491). The derived separation time of C/2002 Q3 from C/2002 Q2 is 1970.2 (+/- 1.2 yr), when the parent comet was at a distance of 56 (+/- 1) AU from the sun, the separation velocity was 0.18 (+/- 0.01) m/s, and C/2002 Q3 (component A) was subjected to a relative deceleration of 34.8 (+/- 1.3) units of 10**-5 solar gravitational acceleration. The predicted separation ephemeris differs very little from that on IAUC 7966. A fragmentation sequence for the components of C/2002 Q3 itself has been determined, based on the astrometry from the period 2002 Sept. 4-14. It is found that (i) nucleus A, the original, eastern component, is the primary, (ii) the component labelled C on Sept. 10 and 14 is identical with C on Sept. 4-5, and (iii) the new, southern condensation from Sept. 10 and 14, called D, is different from B (the observations attributed to B on MPEC 2002-R54 apparently not referring to what was observed on Sept.\ 4--5). [The offsets of B from A on Sept. 4-5 show irreconcilable discrepancies (in excess of 3") when attempts are made to link them with the offsets of the C component on Sept. 10 and 14.] It appears that C separated from A before 1980, a satisfactory solution indicating a fragmentation time in 1973 (+/- 4 yr), at about 52 AU from the sun, a separation velocity of about 0.1 m/s, and a relative deceleration of about 6 units of 10**-5 solar gravitational acceleration. One cannot exclude the possibility that C separated directly from C/2002 Q2 about the time, or even before, component A did. The only satisfactory solution for D suggests that it broke off from A on 2002 July 5 +/- 2 days (at about 1.5 AU from the sun) with a relative velocity of 1.3 m/s and has been subjected to a deceleration of 12 +/- 1 units. The predicted offsets of D from A on Sept. 4-5 are -2".4 in R.A. and -8".9 in Decl. The history of nucleus B remains unknown. Predicted separation distances (and position angles) for components C and D relative to A (0h TT): 2002 Sept. 18, 3".1 (277 deg) and 5".0 (237 deg); 23, 1".5 (245 deg) and 4".7 (292 deg); 28, 1".8 (169 deg) and 7".4 (325 deg); Oct. 3, 3".3 (147 deg) and 10".4 (337 deg); 8, 4".7 (139 deg) and 12".6 (343 deg); 13, 5".7 (134 deg) and 14".1 (346 deg); 18, 6".4 (130 deg) and 15".1 (348 deg); 23, 7".0 (127 deg) and 15".7 (350 deg). [IAUC 7978, 2002 September 25]
, Last observation 2002 September 12, updated 2002 November 6.
It reaches perihelion in November, but unfortunately it is on the opposite side of the Sun to the Earth at the time and will not get brighter than 15th magnitude.
Brian Marsden notes on MPEC 2003-C40 [2003 February 8] that the "original" and "future" barycentric values of 1/a are +0.000058 and -0.000885 (+/- 0.000006) AU**-1, respectively, suggesting that this is a "new" comet from the Oort cloud.
, Last observation 2003 January 11, updated 2003 January 13.
Observations in ICQ format, last observation 2002 December 11, updated 2003 January 6.
It is a distant comet that reaches perihelion next year. Currently around 17th magnitude it will brighten by perhaps a further magnitude. Brian Marsden notes on MPEC 2003-A31 [2003 January 6] that the "original" and "future" barycentric values of 1/a are -0.000007 and -0.000037 (+/- 0.000017) AU**-1, respectively, suggesting that this is a "new" comet from the Oort cloud.
The comet is periodic and is near perihelion and will fade. The period is around 6.7 years and the perihelion distance 1.2 AU. BAA Member Peter Birtwhistle was amongst the first to confirm its cometary nature.
The available astrometry (including prediscovery LINEAR observations from Oct. 4 and 9), the following elliptical orbital elements, and an ephemeris appear on MPEC 2002-T76.
T = 2002 July 25.536 TT Peri. = 359.570
e = 0.44916 Node = 358.796 2000.0
q = 2.11594 AU Incl. = 6.033
a = 3.84130 AU n = 0.130914 P = 7.53 years
[IAUC 7991, 2002 October 12]
Once the orbit was published Kenji Muraoka immediately recognised that the orbit was that of 54P/de Vico- Swift, last seen in 1965.
A. Nakamura, Kuma, Ehime, Japan, reports that K. Muraoka (Kochi, Japan) has identified comet P/2002 T4 (cf. IAUC 7991) with 54P, last seen in 1965. The indicated correction to the prediction on MPC 34423 (ephemeris on MPC 46016) is Delta(T) = -7.5 days. Calculations by B. G. Marsden, Smithsonian Astrophysical Observatory, indicate that the comet passed 0.16 AU from Jupiter on 1968 Oct. 18. [IAUC 7992, 2002 October 13]
The comet is a distant object and reached perihelion at the end of June 2003. It will remain near 17th magnitude until mid 2004. The period is 18.5 years and the perihelion distance 3.93 AU. Observers contributing to the preliminary orbit included BAA Member Peter Birtwhistle.
Although some time from perihelion, it is a distant object in a periodic orbit and will initially fade. The period is around 21.2 years and the perihelion distance 3.4 AU. Observers contributing to the preliminary orbit include BAA Members Peter Birtwhistle and Stephen Laurie.
The available astrometry (some giving the comet's magnitude as bright as 16.5), including an Oct. 12 prediscovery observation, is given on MPEC 2002-U43. It is possible that this comet could reach naked-eye brightness around April--June 2004. [IAUC 8003, 2002 October 29] Observers contributing to the preliminary orbit include BAA Members Peter Birtwhistle and Stephen Laurie. Comet Section contributor Rafael Ferrando also made positional measurements.
H. Kawakita, Gunma Astrononomical Observatory; J. Watanabe, National Astrononomical Observatory of Japan (NAOJ); S. Sasaki and T. Sasaki, University of Tokyo; and N. Takato and T. Fuse, Subaru Telescope, report near-infrared photometry (8".4 aperture) of comet C/2002 T7, obtained on Sept. 14.57 UT with the NAOJ 8.2-m Subaru telescope (+ CISCO) at Mauna Kea: J = 12.7, H = 12.3, K = 12.2. The dust coma has a J-band surface brightness of approximately 20 mag arcsec**-2 and shows an elongated shape of length 20" arcsec in the north-south direction and width 14" in the east-west direction. No tail structure was recognized. [IAUC 8206, 2003 September 22]
W. J. Altenhoff, F. Bertoldi, and K. Menten, Max-Planck- Institut fuer Radioastronomie, Bonn; and C. Thum, Institut de Radio-Astronomie Millimetrique (IRAM), Granada, report the detection of 250-GHz continuum emission from comet C/2002 T7 with the MAMBO bolometer array at the IRAM 30-m telescope, yielding the following flux densities: Feb. 13.636 UT, S = 6.5 +/- 1.1 mJy/beam; 16.697, 8.0 +/- 1.3. These photometric observations with a beam of 11" register emission at the level of 1 mJy also in neighboring channels, suggesting that full-width-at-half-maximum emission extends to a distance of about 20". Around the time of the comet's closest approach to the earth in May, the flux density per beam is expected to increase by a factor 10, and the total flux density by > 100. [IAUC 8292, 2004 February 23]
E. S. Howell, Arecibo Observatory, reports that observations of the 18-cm OH lines in this comet, made with A. J. Lovell and F. P. Schloerb at Arecibo Observatory, result in the following production rates: Apr. 10.63 UT, log Q(OH) = 29.4; 15.60, 29.3; 16.59, 29.4; 17.59, 29.5 (uncertainties of order 10**28 mol/s). Line shapes are consistent with parent outflow velocities ranging from 1.7 to 2.0 km/s. Spectra obtained on Apr. 14-15 reveal an excess of 10-20 percent around cometocentric velocities of +3 km/s. [IAUC 8329, 2004 April 23]
Z. Sekanina, Jet Propulsion Laboratory, writes: "The sudden appearance of a prominent antitail is the result of unusual coincidences. Due to projection effects the antitail could not develop before the end of March 2004, at which time the comet was too close to the sun to be observed from the ground (and not close enough to show up in the SOHO's C3 coronagraphic images). From the orientation in the available images of Apr. 17-20, the dust contained in the antitail is found to have been ejected most probably between discovery (mid-October 2002) and about 300 days before perihelion (the end of June 2003). Because the comet was not brightening dramatically between discovery (except perhaps in the first post-discovery days) and the 2003 conjunction with the sun, it is likely that the material in the antitail dates back to a fairly sudden onset of persistent dust production at or shortly before discovery (i.e., the comet was detected because it 'turned on' at about that time), or the comet's dust-emission activity picked up rapidly in mid-2003, when it was behind the sun. The steeper light curve beginning in August 2003 can support this scenario. In either case, there was no antitail around 2003 Dec. 27 and none is expected to appear around 2004 June 26, the times of the earth's transit across the comet's orbital plane. In the intervening period of time, the position angle of the antitail and the angle it subtends with the prolonged radius vector (i.e., approximately with the plasma tail) are predicted to vary as follows (the first number in each interval refers to an onset time in late June 2003, the second to onset in mid-October 2002): Apr. 15, p.a. 42-45 deg, angle with respect to the radius vector 142-145 deg; 20, 32-37 deg, 137-142 deg; 25, 16-24 deg, 125-133 deg; May 5, 323-334 deg, 80-91 deg; 15, 291-295 deg, 82-86 deg; 20, 274-278 deg, 120-124 deg; 25, 255-262 deg, 130-137 deg; 30, 236-251 deg, 117-132 deg; June 4, 197-232 deg, 80-115 deg; 9, 154-186 deg, 37-69 deg. The angular deviation from the radius vector dropping below 90 deg implies the antitail's disappearance. There are two maxima in this angle, one on Apr. 13, the second on May 21. Unless the dust production terminated early, more recent ejecta fill the entire sector between the antitail and the plasma tail. The visibility of this sector is affected by projection geometry and, to a degree, is anticorrelated with the antitail's prominence. Also, in long- exposure images, which show the antitail to extend further out, its slight curvature may be noticed toward greater position angles (counterclockwise) farther from the comet, although this effect may be concealed by decreasing brightness." [IAUC 8330, 2004 April 23]
M. L. Sitko, University of Cincinnati; R. W. Russell and D. L. Kim, Aerospace Corporation; and S. M. Brafford, University of Dayton, report 3-13-micron spectrophotometry of comet C/2002 T7, obtained on May 31.1 UT with the 1.5-m University of Minnesota telescope (+ Aerospace Broadband Array Spectrograph System; 8".5 aperture; 49" chop throw; integration times 10 min on the comet and 20 min on the reference star, beta Gem) at Mt. Lemmon: "A virtually featureless comet continuum was seen to rise from 3.5 to 13 microns, with only a very weak possible silicate emission band superimposed. A blackbody with a temperature of about 300 +/- 10 K was fit to the underlying continuum flux at 5, 8.4, and 12 microns. This grain temperature is about 9 +/- 4 percent higher than that of an equilibrium blackbody at the heliocentric distance of the comet. The silicate-feature-to-continuum ratio, based on the underlying continuum fit, was about 1.03 +/- 0.02. With our aperture, the comet has the following narrowband (about 0.25 micron) magnitudes and combined random errors (due to calibration star and comet, as well as variations due to the presence of real spectral structure): [3.7 microns] = 7.63 +0.44/-0.31, [4.7 microns] = 5.58 +/- 0.09, [5 microns] = 4.79 +0.49/-0.33, [8 microns] = 1.43 +/- 0.16, [10.5 microns] = 0.06 +/- 0.32, and [12 microns] = -0.39 +/- 0.02 (the stated errors are standard deviations of the mean)." [IAUC 8355, 2004 June 16]
Michael Mattiazzo gives the orbital plane crossings as 2002 December 26, 2003 June 27, 2003 December 25, 2004 December 25.
Brian Marsden notes on MPEC 2004-K65 [2004 May 29] that
The "original" and "future" barycentric values of 1/a from the above orbit are -0.000058 and -0.000697 (+/- 0.000002) AU^-1, respectively. A gravitational solution from the full observed arc is not satisfactory, even when the recent observations are strongly weighted relative to the earlier observations. A nongravitational solution, also not entirely satisfactory, satisfying 3761 observations over the full observed arc with mean residual 0".50, gives A1 = -0.23 +/- 0.02, A2 = +0.28 +/- 0.01.Brian Marsden further notes on MPEC 2004-L38 [2004 June 12] that
Non- gravitational parameters A1 = -0.19 +/- 0.02, A2 = +0.3826 +/- 0.0062 from 3825 observations .The "original" value suggests that this is a "new" comet from the Oort cloud.
Observations made in 2003 August put the comet around 13th magnitude. I observed the comet on September 29.1, estimating it at 11.7 in the N'land refractor x170. The comet appeared significantly brighter than a week earlier. By October 27.03 the comet had brightened to 10.7, with a small 0.7' DC6 coma. It was visible in 25x100B on October 27.95, appearing nearly stellar at mag 11.1 (TK). On November 17.09 it was visible in 25x100B at mag 9.9, with a 1.3' DC5 coma. Several reports in early December put it at around 8.5 with a 2' or larger coma. By mid December observers were reporting significant tail development, unusual in such a distant comet. In mid January I observed the comet in 20x80B making it 7.6, with a 9' diameter coma. By early February the comet had brightened to 7th magnitude, with observers reporting a tail of between 20'and 60'. By early March observers were putting it a little brighter than 7th magnitude, but clearly the rate of brightening has slackened off a little.
Alexandre Amorim recovered the comet after solar conjunction on April 9.36, estimating it at around 4.6. The comet reached perihelion on 2004 April 23 at 0.61 AU. It reached a peak of around 3rd magnitude in the first half of May. It has faded relatively quickly and by early August was around 11th magnitude.
737 observations give a preliminary uncorrected light curve of 5.5 + 5 log d + 6.3 log r though it is currently two magnitudes fainter than indicated by the mean curve.
Observations in ICQ format, last observation 2005 January 8, updated 2005 February 8.
It reaches perihelion at 1.16 AU in early January and could reach 14th magnitude from the end of November. This is LINEAR's 95th comet.
Brian Marsden notes on MPEC 2003-C41 [2003 February 8] that the "original" and "future" barycentric values of 1/a are +0.001075 and +0.000717 (+/- 0.000012) AU**-1 , respectively, suggesting that this is not a "new" comet from the Oort cloud.
The Amor asteroid was recovered in 2007 July and the refined orbit has a period of 5.2 years, with perihelion at 1.17 AU in mid March 2008. It can approach the Earth within 0.26 AU, but remains over 1.2 AU from Jupiter.
M. L. Sitko, University of Cincinnati; and D. K. Lynch, R. W. Russell, and D. Kim, The Aerospace Corporation, report that 3-14- micron spectroscopy of C/2002 V1 (NEAT), obtained on Jan. 9.2 UT with the Aerospace Broadband Array Spectrograph System at the NASA Infrared Telescope Facility 3-m reflector, revealed a thermal- emission spectrum showing a trapezoidal-shaped silicate emission feature with shoulders at 9.0 and 11.2 microns. The underlying continuum was well fitted with a 290-K black body, approximately 14 percent above the black-body radiative equilibrium temperature of 254 K. Narrow-band magnitudes (+/- 0.1) in a 3".5-diameter aperture were M [4.5 microns] = 8.5 and N [10.2 microns] = 3.1. On the following night, the comet was about 10 percent brighter, but otherwise unchanged. [IAUC 8050, 2003 January 15] M. Honda, University of Tokyo, and colleagues (T. Yamashita, H. Kataza, T. Miyata, T. Fujiyoshi, S. Sako, Y. K. Okamoto, T. Onaka, T. Sekiguchi, D. Kinoshita, and J. Watanabe) report on mid- infrared observations of two comets with the 8.2-m Subaru Telescope (+ COMICS). N/Q-band imaging of C/2002 V1 on Jan. 11.2 UT yield the following total fluxes within a 2".73-box aperture: 8.8 microns, 0.83 +/- 0.01 Jy; 11.7 microns, 1.55 +/- 0.02 Jy; 12.4 microns, 1.95 +/- 0.04 Jy; 18.8 microns, 2.79 +/- 0.06 Jy. Low- resolution (250) N-band spectroscopic observations (range 8-13 microns) of C/2002 V1 showed a broad amorphous silicate feature with a 11.2-micron local peak, indicating the presence of crystalline olivine. Total fluxes for C/2001 RX_14 on Jan. 11.6 (measured as above): 8.8 microns, 0.066 +/- 0.004 Jy; 12.4 microns, 0.279 +/- 0.016 Jy; 18.8 microns, 0.356 +/- 0.022 Jy. Low- resolution N-band spectroscopy of C/2001 RX_14 showed the possible shallow silicate feature, but no 11.2-micron local peak was found within the error bars. [IAUC 8053, 2003 January 16]
C. B. Cosmovici, Istituto di Fisica dello Spazio Interplanetario, Consiglio Nazionale delle Ricerche, Rome, reports that he and the rest of the ITASEL team of the Medicina 32-m radio telescope (M. Teodorani, S. Montebugnoli, and G. Maccaferri) detected the 22-GHz water-maser line in comet C/2002 V1 at perihelion, using a fast, high-resolution spectrum analyzer (8192 channels; bandwidth 8 MHz) on Feb. 17, 18, and 19 (when r = 0.101-0.121 AU), during the strong coronal mass ejection (CME) detected by the SOHO spacecraft. The beam size was 2', corresponding to an observed region at the comet of about 80000 km. The mean antenna temperature was 140 +/- 38 mK, giving an integrated flux of 0.70 +/- 0.17 Jy km/s (FHWM = 47 KHz). The neutral water molecules show a velocity shift of -12.2 km/s with respect to the nucleus, confirming the previously observed peculiar strong acceleration of neutral water molecules in C/1996 B2 at perihelion (Cosmovici et al. 1998, Planet. Space Sci. 46, 467; in C/1992 B2, the shift varied between 22 and 44 km/s). Neutral water molecules normally are ejected from the nucleus at velocities around 1 km/s. This peculiarity could be explained by assuming the sublimation of excited water molecules from accelerated ionized icy grains that form an extended source around the nucleus. The strong CME may have contributed to the acceleration mechanism. Evaluation of the water-production rate is in progress. [IAUC 8094, 2003 March 16]
The comet reached perihelion at 0.1 AU on 2003 February 18.3.
Some tentative visual observations in late November suggested that it was approaching 14th magnitude. By early December reports were suggesting that it was around 13th magnitude. I observed the comet with the Northumberland refractor on December 4.94 estimating it at 12.3 and a much easier object than 2001 RX14. A report from Mike Linnolt also suggests that the comet was 12th mag. It seems to be brightening quite rapidly and CCD observations indicate that it is a gassy comet. Reports by December 10 suggested that the comet had brightened to 11th mag. Michael Mattiazzo reported that on December 23.53 it was 9.4, with coma dia.=8', DC=3 in 25x100mm B. I observed it with 14x100B on December 28.76, making it 9.0 with a DC s5, 6.1' coma. Some observers put it as bright as 7.8 by December 30. On January 1.83 it had brightened to 8.2, DC4, diameter 9.0' in my 20x80B. On January 3.91 it was 8.0, but seemed more diffuse at DC3. On January 8.93 it was 7.2 and a little more condensed at DC4. Despite strong moonlight on January 11.80 the comet was quite easy in 20x80B at an estimated magnitude of 6.9. On January 15.74 it was a similar magnitude and appearance. By January 23.75 the condensation had increased to 6, and the coma had shrunk to 6.2', with a total magnitude of 6.2. Observations in late January suggest only a slow brightening, implying that the light curve is flattening further.
By early February tail development was becoming significant with around 2 degrees or more being visible. Moonlight and low altitude are now interfering with observation. With a frontal system sitting over Cambridge on Feb 11 I decided to travel west to find clear skies. After a couple of hours driving I encountered clear skies near Droitwich, and found a country site south of Ombersley. The comet was surprisingly easy in the twilight, showing a short tail and a creamy coloured nucleus. The total magnitude was 3.0, coma diameter 3' and DC8 in 10x50B.
I then travelled south to Antarctica and was able to reobserve the comet from Rothera station in deep twilight on February 25.10 when it was mag 2.9: with a 0.7 degree long tail.
Brian Marsden notes on MPEC 2003-E59 [2003 March 14] that the "original" and "future" barycentric values of 1/a are +0.002297 and +0.001008 (+/- 0.000002) AU**-1, respectively, suggesting that this is not a "new" comet from the Oort cloud.
297 observations received so far give a preliminary light curve, corrected for aperture and where possible for systematic observer differences of m = 7.0 + 5 log d + 9.4 log r which predicted a peak magnitude around -3. It faded more slowly than predicted by the curve.
Observations in ICQ format, last observation 2003 May 3, updated 2004 September 19.
Although a few months from perihelion, it is a distant object and will only brighten a little.
Brian Marsden notes on MPEC 2003-E19 [2003 March 6] that the "original" and "future" barycentric values of 1/a are +0.000447 and +0.000437 (+/- 0.000012) AU**-1, respectively, suggesting that this is not a "new" comet from the Oort cloud.
It was finally confirmed as a comet in 2010 December when observations at the Haute Province Observatory as part of the T2 project showed that it had a tail. This was confirmed by follow-up observations and announced on MPEC 2010-Y29 on December 27. The comet reached perihelion in early January at this return, at a distance of 1.48 AU and has a period of 7.9 years.
Observations made towards the end of August 2003 revealed a clear coma, thus confirming the cometary nature of the object.
An apparently asteroidal object reported by LINEAR (announced on MPEC 2002-V71, where B. G. Marsden noted "whether this object is a comet or not is inconclusive", and MPS 66506) has been found to have a prominent 10" coma with a fanlike morphology spanning p.a. 180-300 deg on images taken by D. Jewitt on Aug. 28.5 UT with the University of Hawaii 2.2-m telescope. Recent astrometry, the orbital elements below, and an ephemeris appear on MPEC 2003-R22. [IAUC 8194, 2003 September 3]
Brian Marsden notes on MPEC 2003-R43 [2003 September 9] that the "original" and "future" barycentric values of 1/a are +0.005297 and +0.005403 (+/- 0.000000) AU**-1, respectively, suggesting that this is not a "new" comet from the Oort cloud.
The preliminary low inclination, small perihelion distance orbit was quickly replaced by a retrograde, larger perihelion distance orbit after Sebastian Hoenig pointed out that no object had been detected in SOHO images. It is some 7 months from perihelion and will brighten by a couple of magnitudes and could reach 14th magnitude in February. Some CCD observations put the comet at 16th magnitude.
Brian Marsden notes on MPEC 2003-C44 [2003 February 8] that the "original" and "future" barycentric values of 1/a are +0.000790 and +0.001222 (+/- 0.000011) AU**-1, respectively, suggesting that this is not a "new" comet from the Oort cloud.
Observations in ICQ format, last observation 2003 January 25, updated 2003 February 1.
It is a moderately distant and intrinsically faint periodic comet of 18th magnitude. Although a few months from perihelion it will fade. It has a period of 8.1 years and a perihelion distance of 2.5 AU.
J. Watanabe, National Astronomical Observatory of Japan, reports the independent visual discovery of this comet by Shigehisa Fujikawa, Oonohara, Kagawa, Japan, (Dec. 14.858 UT, 9:, 4' 0.16-m reflector); report received by Watanabe prior to the issuance of IAUC 8032). T. Lovejoy, Thornlands, Qld., Australia, reports that C/2002 X5 appears faintly visible at mag approximately 10-11 (based on the appearance of other comets in SWAN images) on SWAN images that were taken on six dates, Nov. 6-13, and posted at the SOHO website. [IAUC 8033, 2002 December 16]
R. W. Russell, D. K. Lynch, and D. L. Kim, The Aerospace Corporation; M. L. Sitko, University of Cincinnati; and W. Golisch, NASA Infrared Telescope Facility (IRTF), report that spectroscopy of comet C/2002 X5 was obtained on Jan. 9.1 and 10.05-10.14 UT at 1.5-3.4 airmasses with the Aerospace Broadband Array Spectrograph System at the IRTF 3-m telescope. They observed a relatively smooth thermal-emission spectrum, over most of the spectral range covered (3-14 microns), whose shape resembled a blackbody near or slightly above the blackbody radiative equilibrium temperature of 340 K. A silicate emission feature, if present, would be no more than about 15 percent of the continuum. A 3.4-micron C-H feature may be present in emission. Narrowband magnitudes (each +/- 0.05) on Jan. 9.1 in a 3".5-diameter aperture were L [3.5 microns] = 8.3, M [4.5 microns] = 5.8, and N [10.2 microns] = 1.7. The emission at 10.2 microns was extended at least 18" east-west and 10" north- south, using a 29" north-south chop. The beam only needed to be moved about 3" east-west to get to the half-power location, suggesting that the infrared emission was concentrated on the peak with an extended coma component. On Jan. 10, the spectrum was essentially unchanged, though perhaps 5 percent brighter. [IAUC 8062, 2003 January 30]
Japanese observer Tetsuo Kudo discovered a bright comet on December 13.83 using 20x120 binoculars. It was also reported by Shigehisa Fujikawa on December 14.86 using a 0.16-m f6 reflector x30. Initially reported as 9th magnitude, some observers report it as bright as 7th magnitude. It has a coma perhaps 5' in diameter and a faint tail. [IAUC 8032, 2002 December 14, IAUC 8033, 2002 December 16] The preliminary orbit indicates that the comet could have been found a month ago. Inspection of SOHO SWAN imagery by Terry Lovejoy and confirmed by Sebastian Hoenig has found images that do show the comet and confirm the general form of the orbit and the absolute brightness of the comet.
This is Shigehisa Fujikawa's 6th comet, the others being C/1969 P1 (Fujikawa) C/1970 B1 (Daido-Fujikawa), C/1975 T1 (Mori-Sato-Fujikawa), 72P/Denning-Fujikawa (=1978 T2) and C/1983 J1 (Sugano-Saigusa-Fujikawa). He was also an independent discoverer of C/1968 H1 (Tago-Honda-Yamamoto), C/1968 N1 (Honda) and C/1988 P1 (Machholz). He used nearly the same telescope for these discoveries, but has replaced the original f5 primary mirror with a new f6 one.
After a long spell of overcast skies, it cleared for Cambridge as dusk fell on December 17 and I was able to observe the comet with my 0.15-m reflector x80, making it 8.5, DC3 and diameter 2.4' on December 17.73. This contrasts with observers using binoculars, for example Tony Scarmato, Calabria, Italy on December 17.70 made it 6.7, coma 5' in 7x50B and Guus Gilein from the Netherlands on December 18.21 made it 7.2, coma 5' in 10x50B. I observed it with 20x80B on December 18.73 making it 8.0 with a 5' coma. On December 28.74 I made it 6.9, DC5 in the same binoculars, and on January 1.80 approximately 6.6. Observing in poor conditions on January 10.27 I made it 6.6:, compared to 6.1 on January 7.74. During the second week of January the magnitude seems to have stalled. On January 12.26 under poor conditions I estimated the magnitude at 6.1 in 20x80B. On January 14.28 in brightening skies I found it at 5.8, DC7, diameter 2.3' in 20x80B.
The comet was visible in the SOHO C3 coronagraph from January 25 to 31. It reached perihelion at 0.19 AU on January 29.0, when it showed significant phase angle effects and faded significantly. After perihelion it appeared to brighten again, reaching around 1st magnitude. It has been recovered after conjunction, but a little fainter than expected. Michael Mattiazzo reported it at 5.7 on February 7.51 on 25x100B, low in the twilight.
149 observations received so far give a preliminary light curve, corrected for aperture and where possible for systematic observer differences of m =7.2 + 5 log d + 6.9 log r though it is fading faster than this and is currently some 2 magnitudes fainter than given by the curve.
Observations in ICQ format, last observation 2003 April 5, updated 2004 September 19.
A comet has been found on CCD images (discovery observation below) taken with a 0.12-m f/5.0 refractor by Charles W. Juels (Fountain Hills, AZ) and Paulo R. Holvorcem (Campinas, Brazil). Holvercem reports that co-adding five 45-s and one 90-s exposures taken around Dec. 28.5 UT reveals a coma 1'.8 in diameter. Following posting on the NEO Confirmation Page, several other observers reported on the cometary appearance of the object, including D. T. Durig (Sewanee, TN), who noted that 300-s CCD exposures with a 0.3-m reflector show an inner coma of diameter 30" and a wider, diffuse glow of diameter 2'.5. [IAUC 8039, 2002 December 29]
D. K. Lynch, R. W. Russell, and D. L. Kim, The Aerospace Corporation; M. L. Sitko, University of Cincinnati; and R. B. Perry, Langley Research Center, NASA, report that 3-14-micron spectroscopy of comet C/2002 Y1, obtained on Feb. 20.6 UT with the NASA Infrared Telescope Facility 3-m telescope (+ Aerospace Broadband Array Spectrograph System), yielded a narrowband magnitude of N [10.2 microns] = 3.5 +/- 0.1. The spectrum shows a smooth featureless continuum with an 8-13-micron color temperature of about 280 +/- 20 K, roughly 12 times higher than the radiative equilibrium blackbody temperature. The comet was not detected between 3 and 8 microns, and an upper limit to the silicate emission feature was approximately 10 percent of the 8-13-micron continuum. [IAUC 8083, 2003 February 27]
Notes on the comet mail list suggest that they were using 12cm f5 refractor, on a high-end mount and using a SITe CCD yielding a 2.35 x 2.35 degree field of view. The discovery was made on the very first night the equipment was commissioned!
Paulo Holvorcem provides this background information:
Charles Juels and myself collaborate over the internet, with the help of "fast" ADSL internet connections, which makes it easy to communicate and transfer images in near-real time between Fountain Hills (near Phoenix, Arizona) and my home in Campinas, Brazil. From here I can schedule search and follow-up runs at Fountain Hills using software I wrote for this purpose (or they can be planned by Charles), and we can split the tasks of data analysis by transferring images over the internet. The astrometric observations from codes 926, 848, and 860, which you see in MPECs are obtained in an analogous way. These days I hardly leave my house to observe! We were very lucky to find C/2002 Y1 on the first night with the new 0.12-m refractor on an automated mount. For some time we had considered the idea of doing wide-field searches for new "bright" objects, and this was our first experiment. The field of view is about 2.3 x 2.3 degrees. On that first night (Dec. 28) we searched some 300 square degrees and were surprised to find an object of apparently diffuse appearance. Co-adding the discovery images and a few others taken for follow-up on the same night suggested a coma about 1.8' in diameter, which we didn't immediately report (it seemed too much luck, maybe it was not real). But we reported the positions immediately to the MPC, which posted the object (then referred to as HJ0080) on the NEOCP. It was soon confirmed by others, so we were sure that it was real. And if it was real, then the co-addition of the images showed that it was a comet. We then reported the detection of the coma on Dec. 29, and soon afterwards the comet was announced on an IAUC and a MPEC.
Some observations in early January suggested that it might be around 13th mag. Seiichi Yoshida estimated the comet at mag 10.7 in his 0.32-m reflector on January 11.79 and I made a low reliability estimate of it at 11.6 in the Thorrowgood refractor on January 11.13. Observations later in January after the moon left the sky suggest that the comet had brightened to 10th magnitude. Observing on February 3.1 with 20x80B and 25x100B the comet was a large, diffuse object of approximately magnitude 8. Observing from my bedroom window in Cambridge on April 2.17 I estimated the comet at 6.4 in 20x80B. Southern Hemisphere observers show the comet is slowly fading.
Brian Marsden notes on MPEC 2003-H15 [2003 April 23] that the "original" and "future" barycentric values of 1/a are +0.004102 and +0.004496 (+/- 0.000006) AU**-1, respectively, suggesting that this is not a "new" comet from the Oort cloud. Such comets usually have consistent light curves.
162 observations received so far give a preliminary light curve, corrected for aperture and where possible for systematic observer differences of m = 6.5 + 5 log d + 9.7 log r
Observations in ICQ format, last observation 2003 August 30, updated 2004 September 19.